OP, are you doing carry-on or checking luggage for your flight? Jetblue @JFK is also doing TSA Pre-check "randomly" so Even More Speed might not be necessary, depending on how early you get to T5 (Terminal 5) at JFK which is generally not as busy on a Saturday (even for the upcoming Thanksgiving holiday) - it is, however, their major hub & we always look ahead at the weather "goddness" by 2 to 4 days as we get ready to do OLCI (Online Checkin) to decide on our options.
Fog (thick, soup-like with 1/4 mile visibility) was a factor this morning as I dropped someone else off at the airport & it doesn't have to be snow, rain or a major blizzard.
Security lanes at JFK's T4 are marked & there's uniformed staff & TSA folks checking your mobile/BP to send you onward - and do your bag drops first. If you are "stranded" in the longest & slowest lane with non-speed, non Pre-Check pax - it could take you 15+ to 30 minutes to get thru, so if you flight is boarding & close to departure time, yell out to someone from JetBlue to help so that they can (sometimes) rush you thru. We saw that happened 2 weeks ago flying out of JFK.
If you are doing just carryon luggage, there is a good possibility that if you board late & are the last zone/group to board the aircraft, that all the available overhead bin space for full-sized ++ luggage are gone/taken up already, and FA will be gate-checking your bags at the jetbridge. So, be prepared with a small personal bag (or one that you can unpack quickly or unzip) with all your vital gears, medications & essentials - that can fit underneath the seat in front of you. Generally, they board non-Mint (business/first class) and non-EMSpace max starting from the rear of the aircraft, so rows 26+ or 20+ on the A320's or A321's would have better access to the limited OHB space (as there is simply not enough room for 120+ spinners & rollers on the plane, and, some are loaded sideway while others taking on musical instrument cases are placed above, along with smaller bags that could've gone under the seat.
BTW, welcome to FT's.